The static Method is actually our = operator and it excpects the Value of the type T. In our example T is int
With the Constructor that also expects a value of type T we assign this to our value.
Note, that the OnChange will not trigger with this, because we actually creating a new Model

If you want to trigger the OnChange event, you have to change the value and not the model!

health.Value = 99;

But before we change the Value we need to register a Callback
Something like this: